Abstract: OBJECTIVE To explore the mechanism of Guipi Decoction treating on the depression rats through the measurement of rats serum contents of Triiodothyronine， Thyroxine and Thyrotropin changes.METHODS The depression rat model of depression were established by chronic stress method. Experimental animals were divided into regular group， model group， optimal solution group and Guipi Decoction high， medium and low dose groups. Rats body weight were observed， and open boxes in accordance with experiments conducted on rats behavior detection. Till 42 day in the experiment the rats were sacrificed， femoral artery blood， separation of plasma， serum， measured by radioimmunoassay using rat plasma T₃， T₄ and TSH levels.RESULTS Compared with the regular group， the model group has slower pace of growth of body weight， the scores of horizontal movement and vertical movement reduced， blood T₄ levels reduced， T₃ and TSH levels have remarkable differences. Guipi Decoction in each group and the group optimal solution to increase the growth rate of body weight and movement of behavior science scores， and can add the blood T₄ levels.CONCLUSION Guipi Decoction can add the blood T₄ levels on chronic stress-induced irritation rats and as the role of an antidepressant， which may be corrected through the HPT-axis to achieve.